Plant cell-like tip-growing polymer precipitate with structurally embedded multistimuli sensing ability.

Soft systems that respond to external stimuli, such as heat, magnetic field, and light, find applications in a range of fields including soft robotics, energy harvesting, and biomedicine. However, most of the existing systems exhibit nondirectional, nastic movement as they can neither grow nor sense the direction of stimuli. In this regard, artificial systems are outperformed by organisms capable of directional growth in response to the sense of stimuli or tropic growth. Inspired by tropic growth schemes of plant cells and fungal hyphae, here we report an artificial multistimuli-responsive tropic tip-growing system based on nonsolvent-induced phase separation of polymer solution, where polymer precipitates as its solvent dissolves into surrounding nonsolvent. We provide a theoretical framework to predict the size and velocity of growing precipitates and demonstrate its capability of sensing the directions of gravity, mechanical contact, and light and adjusting its growing direction in response. Exploiting the embedded physical intelligence of sensing and responding to external stimuli, our soft material system achieves multiple tasks including printing 3D structures in a confined space, bypassing mechanical obstacles, and shielded transport of liquids within water.

Avian mud nest architecture by self-secreted saliva.

Mud nests built by swallows (Hirundinidae) and phoebes (Sayornis) are stable granular piles attached to cliffs, walls, or ceilings. Although these birds have been observed to mix saliva with incohesive mud granules, how such biopolymer solutions provide the nest with sufficient strength to support the weight of the residents as well as its own remains elusive. Here, we elucidate the mechanism of strong granular cohesion by the viscoelastic paste of bird saliva through a combination of theoretical analysis and experimental measurements in both natural and artificial nests. Our mathematical model considering the mechanics of mud nest construction allows us to explain the biological observation that all mud-nesting bird species should be lightweight.

Is Hooke's law applicable to an orthodontic cantilever?

INTRODUCTION: This study aimed to analyze the load-deflection characteristics of an orthodontic cantilever by using the large deflection elastic model. METHODS: We experimentally measured the vertical deflections of a cantilever with round or rectangular cross-sections, with lengths of 20 mm and 30 mm, and made of either stainless steel or titanium molybdenum alloy. The measurements were obtained under clinically relevant loading ranges (20-60 g of force for round and 20-140 g of force for rectangular wires) and compared with theoretical predictions derived from small and large deflection elastic models. Load-deflection and tangent stiffness curves were subsequently plotted. RESULTS: The impact of a permanent deformation was clinically insignificant. The stiffness of the cantilever increased with the load or deflection rather than remaining constant. Within the clinical loading range, we identified stiffness reversal loading values at which the stiffness of titanium molybdenum alloy surpassed that of stainless steel. The textbook guidelines on cantilevers can apply only when the vertical deflection remains within 16% of its length. CONCLUSIONS: Within the typical clinical loading range, the load-deflection relationship of a cantilever deviates from Hooke's law because of the prominent deflection trait. The conventional model remains effective when the vertical deflection is within 16% of the cantilever length. Otherwise, it is advisable to determine the load and stiffness on the basis of actual measurements rather than relying on theoretical predictions.

Influence of facial width on the perception of lip protrusion and its differences between profile and 3-dimensional video clip.

INTRODUCTION: This study evaluated the influence of facial width on the perception of lip protrusion and investigated the concordance between 2-dimensional (2D) profile images and 3-dimensional (3D) video clips in assessing lip protrusion. METHODS: An Asian female standard head model was created using 3D modeling software. Eight head models were constructed by modifying the standard head model in terms of facial width (broad, neutral, and slim) and lip protrusion (retrusive, straight, and protrusive). Overall, 97 Asian raters rated the lip protrusion from the 2D profiles and 3D rotation video clips of the 9 models. RESULTS: No significant differences were found in the perception of lip protrusion in terms of sex, age, or occupation. Compared with the 2D profiles, the 3D video clips were rated as more protrusive in 8 of the 9 head models, with the retrusive broad, retrusive neutral, straight broad, and straight slim faces showing statistical significance (P <0.01). The rating is significantly higher in slim faces than in broad faces across the 3 groups of 2D profiles (P <0.01). For 3D video clips, the rating was higher in slim faces than in broad faces in all 3 groups, whereas differences were significant in the straight and protrusive groups only (P <0.01). CONCLUSIONS: In this study, 3D video clips were more sensitive to the perception of lip protrusion than were 2D profiles to some extent. The lips were rated relatively more protrusive in a slim face than in a broad face. Therefore, the relationship between facial width and lip protrusion should be considered in orthodontic treatment goals and treatment plans.

Feasibility and safety of a CaO-SiO2-P2O5-B2O3 bioactive glass ceramic spacer in posterior lumbar interbody fusion compared with polyetheretherketone cage: a prospective randomized controlled trial.

PURPOSE: The CaO-SiO2-P2O5-B2O3 glass-ceramic (BGS-7) spacer is a recently developed spacer that shows chemical bonding to bone with high mechanical stability. Further, this spacer achieves similar results to those of titanium cages. However, evidence regarding the advantages of the BGS-7 spacer is weak compared to polyetheretherketone (PEEK) cage. A randomized controlled trial is therefore warranted. The purpose of this study was to compare the radiographic and clinical efficacies and safety of the BGS-7 spacer compared to those of the PEEK cage in patients who underwent posterior lumbar interbody fusion (PLIF). METHODS: The 54 participants who required one- or two-level PLIF due to lumbar degenerative disorders were randomly assigned to receive a BGS-7 spacer or PEEK cage. Visual analog scale (VAS), Oswestry Disability Index (ODI), European Quality of Life-5 Dimensions (EQ-5D), and painDETECT score were evaluated before surgery and at 3, 6, and 12 months after surgery. The fusion rate, degree of osteolysis, cage migration, and subsidence around the cage (spacer) were evaluated on computer tomography (CT) images at 12 months after surgery. RESULTS: The 12-month fusion rates were 77.8% in the BGS-7 spacer group and 81.0% in the PEEK cage group, with no significant difference (p = 0.807). The result regarding the non-inferiority of BGS-7 spacer was inconclusive. The linear mixed model showed no significant intervention effect in VAS, ODI, EQ-5D, and painDETECT score at the 3-, 6-, or 12-month follow-up. In addition, we found no significant between-group differences in the extent of osteolysis, spacer migration. However, the subsidence around the cage was significantly lower in the BGS-7 spacer group. CONCLUSIONS: This trial found similar fusion rates, and clinicoradiographic outcomes between the BGS-7 spacer and PEEK cage for PLIF. However, the non-inferiority was inconclusive. Safety concerns regarding fracture and migration of the BGS-7 spacer must be considered. Thus, the BGS-7 spacer design for PLIF surgery should be modified before further clinical use.

Efficacy of a novel remotely-generated ultrasonic root canal irrigation system for removing biofilm-mimicking hydrogel from a simulated isthmus model.

AIM: To evaluate the efficacy of a novel ultrasonic irrigation device, remotely-generated irrigation with a non-invasive sound field enhancement (RINSE) system, in removing biofilm-mimicking hydrogel from a simulated isthmus model and compare it with sonically- and ultrasonically-activated irrigation systems. METHODOLOGY: A polycarbonate root canal model containing two standardized root canals (apical diameter of 0.20 mm, 4% taper, 18 mm long with a coronal reservoir) connected by three isthmuses (0.40 mm deep, 2 mm high, 4 mm long) was used as the test model. The isthmuses were filled with a hydroxyapatite powder-containing hydrogel. The canals were filled with irrigant, and the models were randomly assigned to the following activation groups (n = 15): EndoActivator (EA), ultrasonically activated irrigation (UAI), and RINSE system (RS). Syringe irrigation (SI) with a 30G needle served as the control. Standardized images of the isthmuses were taken before and after irrigation, and the amount of hydrogel removed was determined using image analysis software and compared across groups using anova (p < .05). RESULTS: Hydrogel removal was significantly higher with the RS (83.7%) than with UAI, EA, or SI (p ≤ .01). UAI (69.2%) removed significantly more hydrogel than SI and EA (p < .05), while there was no significant difference between SI (24.3%) and EA (25.7%) (p = .978). CONCLUSIONS: RINSE system resulted in the most hydrogel removal, performing better than UAI or EA. The effect of RS was also not reliant on the insert or tip entering the pulp chamber or root canal, making it particularly useful in conservative endodontics.

Minimum required length of orthodontic microimplant: a numerical simulation and clinical validation.

INTRODUCTION: This study aimed to determine the minimum required length of microimplants (MIs) to prevent excessive micromotion during MI healing that can lead to MI failure. METHODS: Hypothesizing that the implantation depth of MI in cancellous bone (IDcancel) is the key to the control of micromotion during MI healing, we numerically investigated the minimum IDcancel required to maintain MI micromotion to below the threshold (30 µm) that would threaten MI survival. Twenty MI and bone models were built using MIs of 4 lengths and bone specimens with 5 different cortical bone thicknesses to create IDcancel in the 0.5-5.5 mm. Then, applying a horizontal force of 1.5 N on the MI head, we calculated the micromotion (peak and average MI micromotions) and determined the minimum IDcancel. A clinical test was performed to verify the numerical result by placing 160 MIs in the posterior maxilla and mandible. RESULTS: A strong correlation (r2= 0.694) was found to exist between IDcancel and MI micromotion. A minimum of 2.5 mm of IDcancel was needed to maintain the level of MI micromotion (peak micromotion) <30 µm threshold. The 6-month survival rate of MI was strongly correlated with IDcancel (r2= 0.744) and decreased sharply when IDcancel was ≤2 mm. CONCLUSIONS: The minimum lengths of MIs to provide the minimum IDcancel of 2.5 mm required to promote successful MI healing in the posterior maxilla and mandible are 5.2 and 6.5 mm, respectively.

Abdominal Actinomycotic Abscess after Laparoscopic Sleeve Gastrectomy for Morbid Obesity: A Case Report.

Actinomycosis is a rare, chronic, suppurative, and granulomatous bacterial disease. The Actinomyces species exist as normal flora in the oropharynx, gastrointestinal tract, and the female genital tract. They are incapable of penetrating the normal mucous membranes and become pathogenic only when this barrier has been destroyed by trauma, surgery, immunosuppression, or after viscus perforation. We report the first case of an actinomycotic abscess after laparoscopic sleeve gastrectomy. A 29-year-old man underwent a laparoscopic sleeve gastrectomy with no intra-operative complications. On postoperative day 3, the patient had a fever with elevated inflammatory markers. Abdominal computerized tomography (CT) with oral water-soluble contrast media showed no extra-luminal leakage and no fluid collection adjacent to the resected stomach, other than the fluid collection in the right subhepatic space. Percutaneous drainage was attempted, but the procedure failed due to the patient's thick abdominal wall. After two weeks of weight loss of about 12 kg, percutaneous drainage was successfully performed, and A. odontolyticus was identified through pus culture. After effective abscess drainage and high-dose antibiotics, the patient's symptoms improved and the abscess pocket disappeared. We reported Actinomyces infection after gastric sleeve surgery. In the case of abscess formation after gastric sleeve surgery caused by actinomycete infection, antibiotic treatment and percutaneous drainage are effective together.

MYB3 plays an important role in lignin and anthocyanin biosynthesis under salt stress condition in Arabidopsis.

KEY MESSAGE: Nuclear-localized Arabidopsis MYB3 functions as a transcriptional repressor for regulation of lignin and anthocyanin biosynthesis under high salt conditions. Salinity stress is a major factor which reduces plant growth and crop yield worldwide. To improve growth of crops in high salinity environments, plant responses to salinity stress must be tightly controlled. Here, to further understand the regulation of plant responses under high salinity conditions, the function of the MYB3 transcription factor was studied as a repressor to control accumulation of lignin and anthocyanin under salt stress conditions. Nuclear-localized MYB3 forms a homodimer. It is ubiquitously expressed, especially in vascular tissues, with expression highly induced by NaCl in tissues such as roots, leaves, stems, and flowers. myb3 mutant plants exhibited longer root growth in high NaCl conditions than wild-type plants. However, several NaCl responsive genes were not significantly altered in myb3 compared to wild-type. Interestingly, high accumulation of lignin and anthocyanin occurred in myb3 under NaCl treatment, as well as increased expression of genes involved in lignin and anthocyanin biosynthesis, such as phenylalanine ammonia lyase 1 (PAL1), cinnamate 4-hydroxylase (C4H), catechol-O-methyltransferase (COMT), 4-coumaric acid-CoA ligase (4CL3), dihydroflavonol reductase (DFR), and leucoanthocyanidin dioxygenase (LDOX). According to yeast two-hybrid screenings, various transcription factors, including anthocyanin regulators Transparent Testa 8 (TT8) and Enhancer of Glabra 3 (EGL3), were isolated as MYB3 interacting proteins. MYB3 was characterized as a transcriptional repressor, with its repressor domain located in the C-terminus. Overall, these results suggest that nuclear-localized MYB3 functions as a transcriptional repressor to control lignin and anthocyanin accumulation under salinity stress conditions.

Treatment of severe mandibular deficiency following TMJ ankyloses by distraction osteogenesis and orthodontic treatment with microimplants.

Severe mandibular deficiency caused by temporomandibular joint (TMJ) ankyloses produces functional and aesthetic problems that require complicated long-term treatment. In this case report, we describe the benefits of using microimplant mechanics for controlling the direction of distraction during distraction osteogenesis and for performing the movement of teeth. We also present its remarkable results and long-term stability. A 20-year-old girl presented with a convex profile due to severe mandibular retrognathia after a history of several TMJ surgeries for bilateral TMJ ankyloses. Mandibular distraction osteogenesis (MDO) was performed, and elastics were placed between the microimplants to control the direction of distraction. Subsequently, after retraction of the maxillary anterior teeth and distalisation of the whole mandibular dentition, the facial profile was markedly improved, and good interdigitation was obtained. The six-year follow-up retention and overall stability were satisfactory with good interdigitation and jaw function.

ACCURACY OF REMOVABLE PARTIAL DENTURE METAL FRAMEWORKS FABRICATED BY COMPUTER-AIDED DESIGN/ COMPUTER-AIDED MANUFACTURING METHOD: A SYSTEMATIC REVIEW AND META-ANALYSIS.

OBJECTIVE: This systematic review and meta-analysis aimed to investigate the accuracy of removable partial denture (RPD) frameworks fabricated by computer-aided design/ computer-aided manufacturing (CAD/CAM) systems compared to frameworks produced by conventional casting methods. METHODS: A systematic literature search was conducted in electronic databases following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, using formulated Boolean operator for searching articles evaluating the fit accuracy of CAD/CAM-fabricated RPD metal frameworks. The agreement of data collection among the reviewers was confirmed using the Cohen kappa coefficient. The modified methodological index for non-randomized studies (MINORS) scale was used to assess the quality of the included studies. Heterogeneity among studies was evaluated, and meta-analyses with global and subgroup analyses were performed. RESULTS: A total of 208 articles were identified with 18 articles available for the narrative review and 7 studies available for meta-analysis on the 3D-printed frameworks for RPD (the overall Cohen kappa coefficient = 0.944). There was no article on the accuracy of RPD frameworks made by milling method. The meta-analysis revealed that the misfit of frameworks obtained with the CAD/CAM method was significantly higher than that of the conventional lost wax and casting method (SMD = 1.23 µm, 95% CI = 0.3610-2.0981 µm, z = 2.77, P = .0055). Regarding the CAD/CAM techniques used for fabricating RPD metal frameworks, the within subgroup analysis showed that the CAD/CAM-based indirect fabrication method produced frameworks with fit accuracy more similar to the conventional lost-wax and casting method (SMD = 1.15 µm, 95% CI = - 0.06136-2.9192 µm, z = 1.28, P < .01) than the CAD/CAM-based direct fabrication method (SMD = 1.35 µm, 95% CI = -0.2722-2.4381 µm, z = 2.45, P < .01), even though there was no statistical difference between the techniques (P = .8482). CONCLUSIONS: The fit accuracy of RPD metal frameworks fabricated by the CAD/CAM method was lower than that of frameworks fabricated by the conventional casting method, but it was within the clinically acceptable range in dimensional misfit. The indirect metal 3D printing technique based on pattern printing and subsequent casting produced frameworks with fit accuracy more similar to the conventional method than the direct fabrication technique.

Agile reversible shape-morphing of particle rafts.

Materials that transform shapes responding to external stimuli can bring unprecedented innovations to soft matter physics, soft robotics, wearable electronics, and architecture. As most conventional soft actuation technologies induce large deformations only in a preprogrammed manner at designated locations, the material systems capable of agile reversible deformations without prescribed patterns are strongly desired for versatile mechanical morphing systems. Here we report a morphable liquid interface coated with dielectric particles, or a particle raft, which can reversibly change its topography under an external electric field. The rafts change from flat floors to towers within seconds, and the morphed structures are even capable of horizontal translation. Our experiments and theory show that the raft deformation is driven by electrostatic attraction between particles and electrodes, while being modulated by electric discharge. A broad range of materials serving as electrodes, e.g., human fingers and transparent polymers, suggests this system's diverse applications, including the human-machine interface and the three-dimensional physical display.

Amination of cotton fiber using polyethyleneimine and its application as an adsorbent to directly remove a harmful cyanobacterial species, Microcystis aeruginosa, from an aqueous medium.

In the present study, we applied an adsorption-based strategy for the removal of a harmful cyanobacterial species, Microcystis aeruginosa, using cotton fiber. Considering the negatively charged surface properties of M. aeruginosa cells in aqueous phases, aminated cotton fibers were prepared through polyethyleneimine (PEI) modification on the pristine cotton fibers. The aminated surface properties of PEI-modified cotton fiber (PEI-cotton) were confirmed by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and potentiometric titration analyses. The pristine cotton fiber could not remove the M. aeruginosa cells, but the PEI-cotton could efficiently remove 98.7% of M. aeruginosa cells from the aqueous medium. In addition, removed cells could be observed on the sorbent surface by field emission scanning electron microscopy (FE-SEM) analysis. PEI-cotton fabricated in 3% PEI solution could remove M. aeruginosa cells (97.9%) more efficiently compared to that fabricated in 1% (82.1%) and 2% (86.2%) of PEI solutions. From the toxicity assessment of the PEI-cotton using Daphnia magna, negligible toxicity of PEI-cotton was confirmed. Our results indicate that the application of PEI-cotton fibers for the removal of M. aeruginosa cells could be suggested as a feasible, effective, and eco-friendly method of harmful algal bloom (HAB) control in water resources.

Process Development for the Detoxification of Fermentation Inhibitors from Acid Pretreated Microalgae Hydrolysate.

The aim of this study was to remove 5-hydroxymethyl furfural (5-HMF) and furfural, known as fermentation inhibitors, in acid pretreated hydrolysates (APH) obtained from Scenedesmus obliquus using activated carbon. Microwave-assisted pretreatment was used to produce APH containing glucose, xylose, and fermentation inhibitors (5-HMF, furfural). The response surface methodology was applied to optimize key detoxification variables such as temperature (16.5-58.5 °C), time (0.5-5.5 h), and solid-liquid (S-L) ratio of activated carbon (0.6-7.4 w/v%). Three variables showed significant effects on the removal of fermentation inhibitors. The optimum detoxification conditions with the maximum removal of fermentation inhibitors and the minimum loss of sugars (glucose and xylose) were as follows: temperature of 36.6 °C, extraction time of 3.86 h, and S-L ratio of 3.3 w/v%. Under these conditions, removal of 5-HMF, furfural, and sugars were 71.6, 83.1, and 2.44%, respectively, which agreed closely with the predicted values. When the APH and detoxified APH were used for ethanol fermentation by S. cerevisiae, the ethanol produced was 38.5% and 84.5% of the theoretical yields, respectively, which confirmed that detoxification using activated carbon was effective in removing fermentation inhibitors and increasing fermentation yield without significant removal of fermentable sugars.

Effect of Viscosity on the Formation of Porous Polydimethylsiloxane for Wearable Device Applications.

Medical devices, which enhance the quality of life, have experienced a gradual increase in demand. Various research groups have attempted to incorporate soft materials such as skin into wearable devices. We developed a stretchable substrate with high elasticity by forming a porous structure on polydimethylsiloxane (PDMS). To optimize the porous structure, we propose a manufacturing process that utilizes a high-pressure steam with different viscosities (400, 800, 2100, and 3000 cP) of an uncured PDMS solution. The proposed method simplifies the manufacturing of porous structures and is cost-effective compared to other technologies. Porous structures of various viscosities were formed, and their electrical and mechanical properties evaluated. Porous PDMS (3000 cP) was formed in a sponge-like three-dimensional porous structure, compared to PDMS formed by other viscosities. The elongation of porous PDMS (3000 cP) was increased by up to 30%, and the relative resistance changed to less than 1000 times with the maximum strain test. The relative resistance increased the initial resistance (R0) by approximately 10 times during the 1500-times repeated cycling tests with 30% strain. As a result, patch-type wearable devices based on soft materials can provide an innovative platform that can connect with the human skin for robotics applications and for continuous health monitoring.

Application of a polyethylenimine-modified polyacrylonitrile-biomass waste composite fiber sorbent for the removal of a harmful cyanobacterial species from an aqueous solution.

Cyanobacterial harmful algal blooms (Cyano-HABs) in water resources involving algal species such as Microcystis aeruginosa have become a serious environmental issue due to their severely negative effects. In the present study, an adsorption-based strategy was employed to control M. aeruginosa, with industrial waste-derived Escherichia coli biomass valorized to produce polyethylenimine-modified polyacrylonitrile-E. coli biomass composite fiber (PEI-PANBF). PEI-PANBF removed approximately 80% of M. aeruginosa cells from an aqueous solution without causing any cell damage. Interestingly, the thickness of PEI-PANBF had a strong influence on the efficiency of M. aeruginosa cell removal. In addition, PEI-PANBF simultaneously removed M. aeruginosa cells and their toxic secondary metabolite, microcystin-LR, from aqueous media. Thus, our proposed fiber represents a feasible utilization method of industrial waste biomass as a biosorbent for the control of Cyano-HABs.

Bladder Regeneration Using a Polycaprolactone Scaffold with a Gradient Structure and Growth Factors in a Partially Cystectomized Rat Model.

BACKGROUND: Tissue engineering can be used for bladder augmentation. However, conventional scaffolds result in fibrosis and graft shrinkage. This study applied an alternative polycaprolactone (PCL)-based scaffold (diameter = 5 mm) with a noble gradient structure and growth factors (GFs) (epidermal growth factor, vascular endothelial growth factor, and basic fibroblast growth factor) to enhance bladder tissue regeneration in a rat model. METHODS: Partially excised urinary bladders of 5-week-old male Slc:SD rats were reconstructed with the scaffold (scaffold group) or the scaffold combined with GFs (GF group) and compared with sham-operated (control group) and untreated rats (partial cystectomy group). Evaluations of bladder volume, histology, immunohistochemistry (IHC), and molecular markers were performed at 4, 8, and 12 weeks after operation. RESULTS: The bladder volumes of the scaffold and GF group recovered to the normal range, and those of the GF group showed more enhanced augmentation. Histological evaluations revealed that the GF group showed more organized urothelial lining, dense extracellular matrix, frequent angiogenesis, and enhanced smooth muscle bundle regeneration than the scaffold group. IHC for α-smooth muscle actin, pan-cytokeratin, α-bungarotoxin, and CD8 revealed that the GF group showed high formation of smooth muscle, blood vessel, urothelium, neuromuscular junction and low immunogenicity. Concordantly, real-time polymerase chain reaction experiments revealed that the GF group showed a higher expression of transcripts associated with smooth muscle and urothelial differentiation. In a 6-month in vivo safety analysis, the GF group showed normal histology. CONCLUSION: This study showed that a PCL scaffold with a gradient structure incorporating GFs improved bladder regeneration functionally and histologically.

pH-Responsive Polypeptide-Based Smart Nano-Carriers for Theranostic Applications.

Smart nano-carriers have attained great significance in the biomedical field due to their versatile and interesting designs with different functionalities. The initial stages of the development of nanocarriers mainly focused on the guest loading efficiency, biocompatibility of the host and the circulation time. Later the requirements of less side effects with more efficacy arose by attributing targetability and stimuli-responsive characteristics to nano-carriers along with their bio- compatibility. Researchers are utilizing many stimuli-responsive polymers for the better release of the guest molecules at the targeted sites. Among these, pH-triggered release achieves increasing importance because of the pH variation in different organ and cancer cells of acidic pH. This specific feature is utilized to release the guest molecules more precisely in the targeted site by designing polymers having specific functionality with the pH dependent morphology change characteristics. In this review, we mainly concert on the pH-responsive polypeptides and some interesting nano-carrier designs for the effective theranostic applications. Also, emphasis is made on pharmaceutical application of the different nano-carriers with respect to the organ, tissue and cellular level pH environment.

Analysis of dental compensation in patients with facial asymmetry using cone-beam computed tomography.

INTRODUCTION: The purpose of this research was to evaluate dental compensation in facial asymmetry and its correlation with skeletal variables using cone-beam computed tomography. METHODS: Sixty adult patients were retrospectively divided into asymmetry (mean age, 21.8 ± 5.4 years) and symmetry groups (mean age, 28.1 ± 4.1 years); both groups comprised 30 patients. Independent and paired t tests were used for comparisons between the asymmetry and symmetry groups and between deviated (Dv) and nondeviated (NDv) sides of the asymmetry group, respectively. Pearson correlation between dental and skeletal variables was performed. RESULTS: The mean value of menton deviation was 9.4 mm in the asymmetry group. Compared with the symmetry group, the direction and amount of dental compensation of the asymmetry group were as follows: 2.5-mm extrusion of the maxillary first molar (UM6) at NDv (P <0.05); 1.8-mm higher position of the mandibular canine (LC) from the mandibular horizontal plane using mental foramen (MHP_mf) at NDv (P <0.05); 6°-more buccoversion of UM6 at Dv; 3.7°-more linguoversion of UM6 at NDv; 4.8°-more buccoversion of the maxillary canine (UC) at Dv; 4.9°-more buccoversion of the mandibular molar (LM6) at NDv; and 2.6°-more linguoversion of LC at Dv. Dental compensation correlated or marginally correlated with skeletal variables of the deviated mandible. CONCLUSIONS: Dental compensations, extrusion of the maxillary molars on the NDv, and buccal tipping of the maxillary teeth and lingual tipping of the mandibular teeth on the Dv, were observed. The mandibular body length was associated with linguoversion of the mandibular molars on the Dv. The ramal inclination was related to the extrusion of the maxillary molars on the NDv.

Long-term changes of the anterior palatal alveolar bone after treatment with bialveolar protrusion, evaluated with computed tomography.

This case report describes the treatment of a 31-year-old woman with a convex profile, protrusive maxilla, retrusive mandible, and gummy smile. Four premolars were extracted, and micro-implant anchorage was used to retract the anterior teeth. Lip protrusion and the gummy smile were improved, but the computed tomography images showed dehiscence on the palatal alveolar bone of the maxillary incisors. Approximately 10 years after treatment, significant alveolar bone apposition was seen on the palatal surface of the maxillary anterior teeth.